Immunohistochemical stains on the colonic adenocarcinoma demonstrate the absence of > and >
protein expression and the presence of > and > protein expression.
Interpretation: Mismatch Repair Protein Panel Abnormal
These results indicate defective DNA mismatch repair (MMR) function within the tumor due to defective < * >. The
absence of < * > may be due to the presence of a germline (heritable) mutation in this/these gene(s). Thus, this individual
and other family members may be at increased risk for having an inherited colon cancer syndrome due to defective DNA
mismatch repair. It is important to note that these results do not distinguish between germline and somatic (not heritable)
alterations. Additional testing is required to distinguish between these two possibilities and to provide predictive testing for
at risk family members. A genetic consultation may be of benefit for this individual and/or family to further discuss the
implications of these findings.
Background:
The majority of Lynch syndrome (hereditary nonpolyposis colorectal cancer) patients demonstrate a germline mutation in
one of the genes involved in DNA mismatch repair, including MSH2 and MLH1 and less frequently MSH6 and PMS2.
Tumors resulting from these mutations generally demonstrate absent MMR protein expression (detectable by
immunohistochemistry). Although immunohistochemical analysis is helpful in suggesting the responsible gene, it does not
distinguish between germline and somatic events, and thus, given the results of the immunohistochemical panel and the
clinical characteristics of the patient, additional workup may be necessary.
CAUTION:
Test results must be interpreted in context of clinical findings, family history, and other laboratory data. False negative
and positive results are possible. If results are inconsistent with the clinical findings, consider additional testing.
The immunohistochemical and/or in situ hybridization tests reported here, except for those addressing Her-2Neu
overexpression, have been developed and their performance characteristics determined by the Immunohistochemistry
and Histology Core Facility laboratories in the Department of Pathology at the OSU Medical Center and are not required
to have nor do they have FDA approval.
Immunohistochemical stains on the colonic adenocarcinoma demonstrate the presence of MLH1,
PMS2, MSH2 and MSH6 protein expression.
Interpretation: Mismatch Repair Protein Panel Normal
The results are indicative of intact DNA mismatch repair (MMR) function within the tumor. It is therefore unlikely that this
individual has an inherited colon cancer syndrome due to defective DNA mismatch repair. We can not rule out the
possibility of an abnormality in one of the other genes involved in DNA mismatch repair or an inherited defect in another
gene not involved in mismatch repair. A genetic consultation may be of benefit for this individual and/or family to further
discuss the implications of these findings.
Background:
The majority of Lynch syndrome (hereditary nonpolyposis colorectal cancer) patients demonstrate a germline mutation in
one of the genes involved in DNA mismatch repair, including MSH2 and MLH1 and less frequently MSH6 and PMS2.
Tumors resulting from these mutations generally demonstrate absent MMR protein expression (detectable by
immunohistochemistry). Although immunohistochemical analysis is helpful in suggesting the responsible gene, it does not
distinguish between germline and somatic events, and thus, given the results of the immunohistochemical panel and the
clinical characteristics of the patient, additional workup may be necessary.
CAUTION:
Test results must be interpreted in context of clinical findings, family history, and other laboratory data. False negative
and positive results are possible. If results are inconsistent with the clinical findings, consider additional testing.
The immunohistochemical and/or in situ hybridization tests reported here, except for those addressing Her-2Neu
overexpression, have been developed and their performance characteristics determined by the Immunohistochemistry
and Histology Core Facility laboratories in the Department of Pathology at the OSU Medical Center and are not required
to have nor do they have FDA approval.